Apparatus for the preparation of acetylene



' Nov, i4; 193.9."

` APPARATUS FOR'TH PREPARATION 0F AcE-TYLEN'E Y Filed Nov, 6,11936 2`shefs-sheet 1 fNov; 14, 12939.'i H. i-loLLER Fri-Al. Y `21v80085AFPARATUS FUR THE PREPARATION oF ACETYLENE Filed Nov. e, 195e 2sheets-sheet V2 I Hermann Hader Oo /Vlues INVENTORS MMT-Kw1* l THEIRATTORNEYS Y process is described as dry generation."

Patented Nov. 14, 1939 UNITED STATES APPARATUS FOR THE PREPARATION 0FACETYLE I Hermann Holler and Otto Mues, Frankfort-onthe-Main, Germany,assignors rto I. G. Farbenindustrie Aktiengesellschaft,Frankfort-on-the- Main, Germany Application November '6, 1936, SerialNo. 109,510

9 Claims.

The present invention relates to an apparatus i'or the preparation ofacetylene from calcium carbide and water.

In the generation of acetylene from calcium carbide by the action ofwater, two processes are known which differ from one another as far asconcerns the residue which remains when the process is completed. Theolder process is described as the wet process and the newer In theformer the residue consists of calcium hydrate Which is obtained as amud-like mass in an excess of water. In the second process the residueis in a pulverulent, dry form which can be used to considerably greateradvantage than of the addition of water likewise requires par` ticularcare because, if too much water is added, a pulverulent product is notobtained, but the lime is agglomerated to'form lumps unsuited for use.

Various methods of overcoming these difficulties have been tried. Byonesuch method the generation is carried out in a long drum, thedimensions of which are such Athat the calcium carbide introducedtogether with the generating waterat the one end of the drum can leavethe -other end of the drum as pulverulent lime. It'is evident that inview of the properties of calcium carbide the operation of the drum hasto be controlled with extreme care in order to obtain the desiredproduct at the outlet of the drum. By another method the calcium carbideis gasied on plates provided with a stirring device, which stirs thecalcium hydroxide and calcium carbide and intimately mixesthe reactingmaterial and thus effects a better ldistribution of the heat of thereaction.

Both these methods 'have the drawback that the elimination of the heatproduced is diflicult and may be insutliciently rapid. A furtherdisadvantage lies in the fact that a layer of calcium hydroxide, throughwhich 'water can penetrate only with difficulty, surrounds the pieces ofcalcium carbide, so that the velocity Germany November 9, 1935 of thegasication in both cases remains relatively small and the calciumcarbide remains associated with the residue until the gasification iscomplete.

The formation of polymerization products is likewise not prevented bythe known processes. As each grainV of calcium carbide is embedded incalcium oxide and calcium hydrate, the gas and the water vapor which are'formed during the gasification can escape only with difficulty. Apocket of gas is formed round the grain of calcium carbide and the watervapor contained in the gas reacts with the calcium carbide and causes itto gasify. Owing to the absence of the cooling action of water, thetemperature rises and soon reaches the upper limit of 150 C. Inl thesecircumstances the formation of polymerization products is possible.

By the present invention these drawbacks are avoided by separating thecalcium oxide and calcium hydrate from the grain of calcium carbide assoon 'as they' are produced. This is attained by gasifying the calciumcarbide in two phases in an apparatus which comprises a chambercontaining one or more sieve-like members adapted to retain and keep inmotion pieces of calcium carbide while they are sprayed' with water, and'a surface of relatively great extension adapted to receive pulverulentmaterial from the sieve-like member or members, means -being provided tokeep in motion the material on the said surface so that good contact ismaintained between the particles of material and the atmosphere of thechamber. The sievelike member may advantageously be a revolving screenwhich contains the calcimn carbide to be gasied and below which there isarranged a system of one or more revolving plates above each of whichthere is arranged a device for Vmoving the reaction material overptheplates, for instance, a stirring worm. 'I'he revolving plates altogetherhave herein a relatively large area when compared with that of thesurface of the revolving screens.

All the aforesaid parts are enclosed by a cas- 45 ing to prevent theundesirable escape of the acetylene generated.

Whereas in known generators only pulverulentfcalcium carbide can ,betreated, by the new arrangement it is possible tov use non-classifiedgrains f calcium carbide. The subdivision of the generating process hasthe advantage that in the first phase the gasification velocity isacceleratedbecause the calcium hydroxide which is mixed with a smallvquantity of small pieces `455 f bide which reach the plates, thematerial which has passed through the sieve is rotated by means of astirring device until the grains of calcium carbide are gasified by thetraces of water still contained in the residue of lime or of Water vaporcontained in the acetylene.

The stirring of the residue serves to produce a uniform product. As isknown, technical calcium carbide contains up to about 15 per cent. ofimpurities which are distributed irregularly. Unstirred residue would,therefore, show the same irregularity of distribution of impurities. Bystirring the residue the impurities are uniformly distributed, thisbeing of advantage in the uses to which the residue is applied.

In 'order to avoid the vpolymerization when the generator is not in useand the moisture contained therein enters into reaction with the calciumcarbide not yet gasified, the motion of the calcium carbide ismaintained when withdrawal of the gas is temporarily suspended, be itfor a short` or prolonged period. In order to prevent polymerization itis therefore advisable to disengage the generator only after the freemoisture contained therein has been utilized.

In order that the gasification should proceed smoothly, it is necessarythat the calcium car.- bide and the product obtained during thegasification should move continuously through the plant. To this end theopenings of the revolving screen should be large enough to avoidclogging. Furthermore, it is advisable to provide means for keeping theopenings always clean and free for example brushes, scrapers or the likewhich are suitably mounted in such a manner that they act on both sidesof the revolving screen. In this case care has to be taken that duringthe cleaning process no sparks are produced by'v the friction of thebrushes at the wall of the drum. A material which does not producesparks is, therefore, preferably used for the drum or the brushes, orboth. the other part being made of steel. The only limitation ofimportance on the material used is that no sparks are produced byfriction between the rubbing parts.

In the second phase no disturbances in the movement of the productobtained are likely to occur so that in this case it is not necessary toprovide cleaning devices or the like.

In the accompanying drawings an acetylene generator according to theinvention is diagrammatically illustrated by way of example.

Fig. 1 isa vertical section through the entire plant and Fig. 2 is a.partial section on line I-I of Fig. 1.

Fig. 3 is a plan view of one of the revolving plates schematicallyillustrating the use of a plurality of stirring worms. -k

Fig. 4 is a vertical sectional view of`a plant showing a plurality ofrevolving screens.

The calcium carbide leaves the storing hopper i, passes the chargingdrum 2 and enters the revolving screen 3 which is caused to rotate bythe shaft 4. 'Ihe water is introduced through the pipe 5 provided with anumber of nozzles by means of which the water is sprayed as uniform lyas possible on the calcium carbide 6 contained in the revolving screen3. By the brushes 'I and 8 the openings through which the materialpasses from the revolving screen 3 are permanently kept clean. Thebrushes are mounted in the interior and at the outside of the revolvingscreen 3.

By the motion of the drum 3 the residue which is formed during thegasification at the surface of the grains of calcium carbide 6 is rubbedoff and falls through the openings of the drum on to the system ofrotating plates 9 mounted below 'the drum. The plates 9 are arranged oneabove the other and above each there is mounted a stirring worm l0 whichgradually moves the material to the bottom, while uniformly rotating it,until it reaches the collecting vessel Il in the form of dry pulverulentlime. From time to time the lime is discharged from vessel I i.

It is obvious that instead of one worm, several worms may be arrangedabove each plate as shown in Fig. 3; the worms may also be substitutedby rakes or scrapers or other means which move the material over theplates.

The acetylene produced leaves the generator, passes through the tube i 2and enters into the condenser and the gas holder from which it isdistributed to the consumer.

In addition to the revolving screen 3, further drums of the same kindmay also be mounted in positions adjacent to one another as shown inFig. 4. It is also possible to replace the system of plates 9 the numberof which may be chosen according to the conditions required in eachcase, by equivalent devices, for instance plates of large area, and,therefore. having a large operative surface; the material placed thereonis kept in motion in known manner.

We claim:

1. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained which apparatus comprises at least one revolving screen for thereception of the calcium carbide to be gasifled, a water inlet pipearranged above the axis of each revolving screen and having at least oneexit opening so that only the carbide within this screen is moistened,at least one revolving plate mounted below the revolving screen and atleast one means mounted above the plate for moving the reacting materialover the plates and a casing enclosing all the aforesaid parts.

2. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained which apparatus comprises at least one revolving screen for thereception of the calcium carbide to be gasified, a water inlet pipehaving at least one exit opening, at least one revolving plate mountedbelow the revolving screen and at least one stirring worm mounted abovethe revolving plate and a casing enclosing all the aforesaid parts.

3. A device for generating acetylene from calcium carbide and water; thequantity of water added being limited so that a pulverulent residue isobtained which apparatus comprises at least one revolving screen for thereception of the calcium carbide to be gasified.' cleaning means incontact with the walls, of the revolving screen, a water inlet pipehaving at least one 75 exit opening, at least one revolving platemounted below the revolving screen and at least one means mounted abovethe plate for moving the reacting material over the plate and a casingenclosing all the aforesaid parts.

4. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained which apparatus comprises at least one revolving screen for thereception of the calcium carbide to be gasifled, brushes or Scrapers incontact with the walls, of the revolving screen, a water inlet pipehaving at least one exit opening, at least one revolving plate mountedbelow the revolving screen and a device mounted above the plate formoving the reacting material over the plate and a casing enclosing allthe aforesaid parts.

5. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained which apparatus comprises at least one revolving screen for thereception of the calciumcarbide to be gasied, brushes or scrapers incontact with the walls of the revolving screen, a water inlet pipehaving at least one exit opening, at least one revolving plate mountedbelow the revolving screen and at least one revolving worm mounted abovethe plate for moving the reacting material over the plate and a casingenclosing all the aforesaid parts.

6. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained, which apparatus comprises at least one revolving screen forthe reception of the calcium carbide to be gasiiled, cleaning means incontact with the walls, of the revolving screen, a water inlet pipehaving at least one exit opening, at least one revolving plate mountedbelow the revolving screen and at least one means mounted above theplate for moving the reacting material over the plate and a casingenclosing all the aforesaid parts.

7. A device for generating acetylene from calcium carbide and water, thequantity of water added being limited so that a pulverulent residue isobtained. which apparatus comprises at least one revolving screen forthe reception of the calcium carbide to be gasied, cleaning means of amaterial not forming sparks in contact with the walls, of the revolvingscreen, a water inlet pipe having at least one exit opening, at leastone revolving plate mounted below the revolving screen and at least onemeans mounted above the plate for moving the reacting material over theplate and a casing enclosing all the aforesaid parts.

8. A device for generating acetylene from calcium carbide and Water, thequantity of water added being limited so that a pulverulent residue isobtained, which apparatus comprises at least one revolving screen of amaterial not forming sparks for the reception of the calcium carbide tobe gasifled, cleaning means of a material not forming sparks in contactwith the walls, of the revolving screen, a water inlet pipe having atleast one exit opening, at least one revolving plate mounted below therevolving screen and a device mounted above the plate for moving thereacting material over the plate and a casing enclosing all theaforesaid parts.

9. A device for generating acetylene from calcium carbide and water, thequantity o1 water added being limited so that a pulverulent residue isobtained, which apparatus comprises a revolving screen for the receptionof the calcium carbide to be gasifled, a water inlet pipe having severalexit openings, several plates mounted below the revolving screen and astirring worm mounted above each plate for moving the reacting materialover the plates and a lcasing enclosing all the aforesaid parts.

OTTOMUES.

